• Bone regenerative response following bone augmentation using hydroxyapatite with and without growth factors

      Sohn, Jeong-Yeol; School of Graduate Studies (1997-09)
      The purpose of this study was to determine whether adding transforming growth factor-13 (TGF-13) which is known to promote osteogenesis or 15 amino acid polypeptide obtained from collagen type I (P-15) which is known to enhance DNA synthesis in cultured fibroblasts, would enhance the osseoint~gr.ation- of porous anorganic bovine bone block (HA-block) to mandibular bone surface. Total of 45 rabbits were divided into three equal groups. The buccal side of the mandible in ea.ch anesthetized animal was surgically exposed,. decorticated and 10 x 5 x 4 mm. HA (Group I), HA+ TGF-13 (Group II) or HA + P-15 (Group III) blocks. were affixed to .host bone using two, titanium screws. Animals were sacrificed, 1 wk, 4 wks and 8 wks after surgery. A core of the implant· and underlying host bone was used to determin.e osteocalcin using Western and Slot blot analyses before perfusing the animals with 4% forma}in. The contralateral sides were only decorticated and served as sham controls. The interface between the HAblock and the ho.st bone showed a signifi.cantly higher (P<0~05) number of mesenchymal cells in the HA + TGF--P. and HA + P-15 one week group when c.ompared. to HA-alone. This numb.er of mesenchymal ·cells declined significantly .by the 4th and 8th weeks. The proliferating cell nuclear antigen (PCNA) index using immunohistochemistry als.o showed a significant increase in the one week groups and· then also declined. Alkaline phosphatase, osteocalcin, bone volume, and new bone formation were all significantly increased by the 4th and 8th weeks and were significantly higher in the HA + TGF-13 and HA + P-15 at 4 wks after surgery. In addition, the macropores of the lower halves of all blocks were filled with new bo.ne. The den~ity of the newly formed bone was comparable to the control bone. These res.ults indicate that anorganic :bovine bQne blocks are osteoconductive and their pores permit growth of new bone. The adding of TGF-P or P-15 enhanced all parameters of osteogenesis at the mandibular bone surface.
    • he relationship between self-concept and locus of control on tobacco use among rural black and white preadolescents: a comparative study

      Smith, Teresita Maria; School of Graduate Studies (2003-03)
      This study investigated the relationships among demog·raphic variables- of grade, age, gender, and race; self-_concept related to home, school,. and peer; and internal and external locus of control on tobacco use among rural BJack and White preadolescents using a cross-sectional design. The sample consisted of 666 preadolescents •in grades 4 and 5, ages 8 through 12, and enrolled in public schools in east central Georgia. Five elementary schools met the inclusion criteria of being located in a rural county with a population < 25,000, and also with > 50% Black student enrollment. Individual classrooms were randomly selected in 3 of the-schools. All fourth and fifth graders were selected in the other 2 schools. Data were analyzed using descriptive statistics, chi-square, t test, and 6 . . logistic regression. Independent variables were self-concept and locus·of control. The dependent variable was tobacco use as being use or never use. The 54-item self-report survey was compri_sed of 4 brief scales: the Student Information Data . Form; the. Hare Self-Este.em Scale; the Nowicki-Strickland Children's Locus of Control. Scale; and the Tobacco Use Self-Report. Data were collected during Fall 2002 and involved 2 steps: (1) Explanation of the study and th~opportunity to participate were provided to the students (parental consent and child assent forms were obtained fro~ those agreeing to participate), and (2) data collection was ·conducted using_ the self-report survey form.· The study.found that tobacco use.rs totaled 9.2°/o' of the sample, which was gre.ater than the· rural norm of 4.2% to 5%. The sample of Black participants was _ large, s·1. 7%, as compared to previous studies with 0% to 20%, an~ was representative of the population. Those who used tobacco 'were more likely to be ' . boys (OR= 2.66, p = ~0005); have low:home sel.f-concept s.core (OR=. 0.91, p = .0003); have low school self-concept score (OR= 0.91, p < .0001 ); and have external locus of control (OR·= 2.05, p = .008) than those who did not use tobacco. Further studies· are recommended that may identify other contributing factors of tobacco use among rural preadolescents, such as diet, exercise, health, and sociodemographic variables.
    • An autoregulatory process for androgen production in rat ovarian thecal-interstitial cells

      Simone, Deborah; Department of Physiology and Endocrinology (1992-10)
    • Role and significance of bradykinin in reproduction

      Shi, Beien; School of Graduate Studies (1998-04)
    • Angiotensin II signaling mechanisms involved in the elevation of arginase activity/expression and vascular dysfunction

      Shatanawi, Alia; School of Graduate Studies (2011-11)
      Vascular endothelial dysfunction is a major cause of morbidity and mortality in · patients with cardiovascular diseases such as hypertension, atherosclerosis and diabetes. Nitric oxide (NO) produced by endothelial nitric oxide synthase (NOS) is· needed for norm.al vascular function. During hypertension, diabetes or -atherosclerosis, elevated levels of arginase can compete with NOS for available L-arginine thus reducing vascular NO production. Elevated angiotensin II (Ang II) is a key participant of endothelial dysfunction in many cardiovascular diseases and has been linked to elevated arginase activity. In this· study we explored the signaling pathway leading to increased arginase expression/activity in responses to Ang II.in bovine aortic endothelial cells (BAEC). Treatment of BAEC with Ang II (10-7 _M, 24 hrs) caused a 40±6% increase in arginase activity. This was accompanied by 30±8% decrease in NO production. Our studies indicate involvement of the RhoA/ROCK-p38 mitogen activated protein kinase (MAPK) in Ang 11.,induced arginase upregulation and reduced NO production, as inhibitors of ROCK or p38 MAPK prevented the Ang II-induced increase in arginase activity. Our studies in mice also show involvement of p38 MAPK in Ang II-induced vascular dysfunction associated with elevated arginase activity and expression. Ang 11 (42 · μg/kg/h) caused impaired EC-dependeht vasorelaxation in mouse . aorta (55±7~ vs. -75±8% for control}. This ·impairment was prevented by treatment with p38 inhibitor S8203580. (5 μg/kg/day). Ang II also caused a 6.2 fold increase in vascular arginase activity/expression that was complete_ly prevented by p38 MAPK inhibition. Additionally, treatment of BAEC with Ang II causes phosphorylation of activating transcription factor-2 (ATF-2) and -enhancement of the binding of ATF-2 to arginase promoter through an AP-1 site . as evident from electrophoretic mobility shift assay experiments. Transfection of BAEC with ATF-2 siRNA prevents Ang II-induced increases in arginase activity/expression and maintains NO production. These results indicate that. ATF-2 is necessary for enhanced expression of arginase by Ang II. Collectively, our results indicate that Ang 11 increases endothelial arginase activity/expression through a RhoA/ROCK-p38 MAPK-ATF-2 pathway leading to reduced NO production and endothelial dysfunction. Targeting these signaling steps might be therapeutic points for preventing vascular endothelial dysfunction_ associated with · elevated arginase activity/expression.
    • Self-care and cultural meanings of mothering in african american women with hiv/aids.

      Shambley-Ebron, Donna; School of Graduate Studies (2003-11)
      African American women who are HIV-positive and responsible for mothering an HIV-positive child face many challenges in caring for themselves and their children. This study used critical ethnographic methods to explore the experiences, values, traditions ·and beliefs of African American women to understand how these factors influence self-care and mothering. An Africana Womanist framework was used to guide this study. The study was conducted with a purposive sample of 10. African American · women from the Southeastern United States. The sample participants were HIV-positive and had at least one child who also was HIV-po~itive. The overarching theme derived from the research was "Creating a Life of Meaning", which encompassed domains of · "Disabling Relationships, "Strong Mothering", and "Redefining Self-Care". This study revealed the culturally. specific ways in which African American women mother their children and manage their own care when. living with HIV, a chronic, stigmatizing illness. This study dispels negative stereotypes of African American women and highlights the sttengt}ls ·that women use in their daily lives. This research has the potential to create an impact on the ways in which nursing care is delivered. and self-care promoted for this population.
    • Development of an occupational therapy education program for a technical institute

      Schumann, Sandra H.; School of Graduate Studies (1999-04)
    • An examination of telenursing : description of the professional role and predictors of role stress, role ambiguity and role conflict

      Schlachta-Fairchild, Loretta M.; School of Graduate Studies (2000-11-07)
      An examination of telenursing: Description of the professional role and predictors of role stress, role ambiguity and role conflict. Telenursing is the use of telehealth technology to deliver nursing care and conduct nursing practice (Schlachta & Sparks, 1999). In response to the rapid adoption of telemedicine technology in he'1:lthcare organizations, telenursing is emerging as a new role, prompting discussion of licensure, malpractice, and credentialing issues within nursing. Role stress associated with new nursing roles such as telenursing impacts individual patients and the larger healthcare organization, causing turnover, burnout, loss of continuity of care and loss of operational expertise. As with many emerging technologies, nurses assume increasingly complex roles and responsibilities. As telemedicine proliferates, the role of nurses in participating in and improving the telemedicine process will take on more pr.ominence. It is important to identify issues related to use and integration of telemedicine into nurses' roles to minimize role stress, encourage telenursing participation and position nursing practice to take advantage of telemedicine technologi~s. Using the portion of Role Theory, that relates to the impact of Role Set upon Role· Strain, as a framework this was a descriptive ·research study that identified a current population of 796 telenurses in the U.S., representi!lg 40 states. From this population, 196 telenurses participated in a telephonic or an online, web-based survey during Summer 2000. The purposes were to 1) Describe a) telenurses' professional role(s) and characteristics and b) U.S. strategies for nursing competence and patient safety 2) Measure telenurses' work satisfaction_ and its components, and role stress and its components 3) Predict the relationship between the components of work satisfaction, individual and professional role characteristics, and role stress, role ambiguity and role conflict. iv Findings of the Telenursing Role Study indicated that the typical Y2K telenurse is 46 years old, has worked 21 years in nursing and >6 months in her telenursing position. She has a 27% chance of being an advanced practice nurse, and has at least a baccalaureate degree, and likely a graduate degree. The typical telenurse is white, female, married, and has children .. She works full-time in teleriursing and makes just over $49,000 per year. Telenurse.s work in over 29 practice settings, including web portals, private companies and for telemedicine equipment vendors. They have a host of unique, new titles such as Bioengineering Clinical Nurse Specialist, Telehealth Project Director and Consumer Information Nurse. Telenurses experience less than average role stress, role ambiguity and role conflict. They also have the same work satisfaction as other hospital-based nurses. The most important factor contributing to telenurses' work satisfaction is autonomy. Findings of regression analysis were that education level and level of work satisfaction both predict role stress and role ambiguity in telenurses. Higher education levels of telenurses are associated with higher role stress and role ambiguity. Higher levels of work satisfaction of telenurses are associated with lower role stress and role ambiguity. Role ambiguity, level of education and work satisfaction are significant predictors of role conflict in telenurses.
    • Determinants of quality of the caregiving relationship

      Sauter, Maranah A.; Determinants of quality of the caregiving relationship (1996-10)
    • Implications based on these results support the need for critical care nurses to use caution to avoid overestimating parental stress. Parents should be included in care of the child whenever possible,· and recognized for their uniqu~ ability to parent their child, even when critically ill.

      Sanders, Cindy L.; School of Nursing (1993-03)
      Th~ admission of a child to the PICU is stressful t6 parents of that child. Critical care nurses caring f~r these critically ill children and their families are in a unique position to assess parental str~ss. The purpose of this st~dy was to compare nurses' (n=30) and parents• (n=30) perceptions of· parental strassors in the PICU, as,measured by scores 6n the Parental Str~ssor s6ale: Pediatric Intensive Care· (PSS: PICU) developed by Miles and Carter (1982). Differences between parents 1 and nurses' mean scores on the total PSS:PICU and each of seven dimertsibnai scores were analyzed using paired t-tests. Significantly higher scores were found for nurses in bo€h total PSS:PICU and four of seven sub,scales. Analysis of mean scores between mothers and fath~rs, nurses who ~ere afid were n6t parants, arid nurses wfth less than ·five and greater than fi'(e year-s PICU experience showed ·no significant differences. Parents who experienced unplanned PICU admissions scored signiticantly _higher than parents whose child's admission was planned on the dimension of child's appearance. Implications based on these results support the need for critical care nurses to use caution to avoid overestimating parental stress. Parents should be included in care of the child whenever possible,· and recognized for their uniqu~ ability to parent their child, even when critically ill.
    • An unusual DNA sequence observed in the [gamma] globin gene loci of two members of a Chinese family

      Ryan, Qin Cao; Department of Cell and Molecular Biology (1989-05)
      There are two nonallelic human y globin genes located on the short arm of ~hromosome #11 in the order 5'-Gy-Ay-3'. Various modifications of the two y genes have been reported and include: deletion·s., triplications., quadruplications and recently a quintuplication. These are :.generally created by one or more unequal crossovers in the y globin ge~e- _regions on adjacent chromosomes. During the c~urse of looking for a y0 thala~semia,. which might be due to a_ crossover within the y genes., two cases were found in the family W. · Bgl II mapping studies showed a 5 kb deletion at the y gene loci in these individuals. The ·Bgl II fragment from th(= y gene loci of R .W. was cloned into the phage vector ·oRl. Phage mapping showed that two out o·f the three Pst I sites within the Bgl II fragment were missing which suggested that the crossover might· have occurred within the y gene., possibly within the yIVS II region. Sequence analysis of the cloned fragment revealed an unusual sequence which had no sequence homology with the r gene region except for a small 264 .bp region near the 3' end. The orientation of the 264 bp fragmen~ is inverted _relat~ve to homologous sequences in the Gr and A'Y IVS II. . The unus~al sequence was computer analyzed for homology with every DNA sequence file in the EMBL data base and GenBank and did not show ·any significant homologies to._ all the available DNA sequences except for the 264 ~p _yIVS II homology. Sine~ mor~ than 99% of the DNA sequences in. the whole of nature still remain unknown., ~he origin of this unusual sequence is a question which mu.st ~wait further investigation.
    • Hypothalamic AgRP and POMC neurons modulate stress-induced depression-related behaviors

      Fang, Xing; Department of Neuroscience and Regenerative Medicine
      Depression is a common and debilitating mental disease. Currently available antidepressants are not effective for many individuals with depression and our understanding of the underlying mechanisms remain limited. Evidence suggests that hypothalamic arcuate nucleus (ARC) is highly responsive to acute stress. The ARC contains two distinct subpopulations of neurons—expressing orexigenic agouti-related peptide (AgRP) and anorexigenic pro-opiomelanocortin (POMC). AgRP and POMC neurons regulate food intake and the food reward system. It is unknown whether AgRP and POMC neurons are recruited by chronic stress and if their dysfunction may contribute to the development of chronic stress-induced depression-related behaviors. To address this, we have developed a mouse model of chronic unpredictable stress (CUS), which can induce anhedonia and despair behavior that mimic symptoms in human depression. Using this animal model, I investigated the roles of AgRP and POMC neurons in stress responses and stress-induced depression-related behaviors. I demonstrated that CUS decreases activity of AgRP neurons but increases activity of POMC neurons. A chemogenetic approach was used to selectively manipulate the activity of POMC and AgRP neurons, leading to opposite effects of stress-induced depression-related behaviors. These results suggest that AgRP and POMC neurons are differentially involved in stress maladaptation and related behaviors. It provides insight into the mechanisms underlying the development of depression and novel strategies for the treatment of this mental illness.
    • The effects of metronidazole on murine (mus musculus) bone-cell culture

      Rouse, Stephen J.; School of Oral Biology (1998-05)
    • Androgenic maintenance of rat penile erection

      Reily, Christopher M.; School of Graduate Studies (1997-06)
    • Venous contraction to endothelin-1 in congestive heart failure.

      Reddy, Vikram; School of Graduate Studies (2003-04)
      Endothelin-1 (ET-1) is produced by endothelial cells and can stimulate either the ET A or the ET 8 receptors. The role of ET-1 and the identity of the endothelin receptors involved in mediating tone in the mesenteric small veins of the -Golden Syrian hamster are not known. ET-1. induces venoconstriction, thereby increasing the preload to the heart in congestive heart failure. However, mechanisms mediating contraction to ET-1 in the mesenteric small veins of the cardiomyopathic hamsters in the early and late stages of CHF are not known. Therefore, mechanisms mediating ET-1 induced contraction were determined in the mesenteric small veins of the Golden Syrian and cardiomyopathic hamsters in the early and late sta~es of CHF. Baseline intraluminal diameter of small veins was measured before anci after treatment with either ET A or ET 8 receptor antagonists. .ET-1 induced contraction was higher in the · early stage of CHF, while it was· decreased in the late stage of CHF. Blockade of the ET A receptor decreased ET-1 induced contraction in the mesenteric small veins from the control and cardiomyopathic hamsters in both the early and late stage of CHF. ET 8 receptor blockade decreased the ET-1 induced contraction in the control and cardiomyopathic hamsters in the early, but not late, stage of CHF. Therefore, ET-1 induced contraction in the mesenteric small veins is mediated by the ET A receptors alone in the late stage of CHF, while both the ET A and ET 8 receptors mediate vasoconstriction in the controls and in the early stage of CHF. Stimulation of ET-1 receptors is associated with an increase in calcium levels within the vascular smooth muscle cells. It is not known whether the increase in reactivity to ET-1 in the early stage of CHF or the decrease in reactivity to ET-1 in the late stage of CHF is due to problems with mobilization of the intracellular calcium levels within the vascular smooth muscle cell. Following ET-1, calcium levels within the vascular smooth muscle cell were increased to a larger extent in the early stage of CHF, than in the late stage _of CHF, in agreement with the vascular reactivity data. Calcium levels were also measured before and after treatment with either ET A or ET B receptor antagonists. Blockade of the ETA receptor inhibited the ET-1. ·induced increase in calcium levels in the mesenteric small veins from the control and cardiomyopathic hamsters in both the early and late stage of CHF. However, ETa_ receptor blockade inhibited the ET-1 induced increase in calcium levels in only the control and cardiomyopathic hamsters in the early stage of CHF. These results indicate the absence of a functional responses mediated by the ET a receptor in the late stage of CHF. Studies have shown that NO can modulate the contraction to ET-1 in the vasculature. Baseline intraluminal diameter of small veins were measured before and after treatment with N-nitro-L-arginine (LNA), a specific inhibitor of nitric oxide · synthase. LNA decreased the contraction to ET-1 in the early stage of CHF, but increased contraction to ET-1 in the late stage of CHF. This indicates thatNOS mediates a vasodilatory effect that counteracts contraction to ET-1 in the late stage, but contributes to the vasoconstrictor effect of ET-1 in the late stage of CHF. NOS activity was. measured to identify the NOS isoforms contributing to the modulation of ET-1 induced vascular reactivity. Total NOS activity was significantly increased in the cytosolic fraction of small veins from hamsters in the late stage of CHF and in the particulate fraction in hamsters in the early stage of CHF. In the late stage, the increase in NOS activity was inhibitable by 1400W, an iNOS selective inhibitor, suggesting that an increase in iNOS decreases the contraction to ET-1. In summary, in the early stage of CHF, there is an increase in the vascular reactivity to ET-1 associated with an increase in intracellular calcium levels and partially mediated by NOS. This may-increase preload and impair myocardial function in CHF. There is an absence of ET 8 receptor-mediated responses in the late stage of CHF, associated with very high plasma ET -1 levels and imp•aired intracellular calcium · signaling. NOS activity is significantly enhance4 in the mesenteric small veins from the cardiomyopathic hamsters in the late phase of CHF, and this increase in NOS activity is at least partially dependent on iNOS and may contribute to impaired venous contraction to ET-1 in cardiomyopathic hamsters. This may serve as a compensatory mechanism to decrease the preload to the failing heart.
    • The effects of age and endotoxin on antioxidant enzyme activity in the eye

      Recasens, Jaime F.; Department of Ophthalmology (1990-06)